How to Know What Size Drill Bit to Use: Essential Guide for Homeowners

Drills are one of the most common items in the average consumer's arsenal of tools. They’re a must have for many and work for a wide range of projects. This being said, there may be some things about your much beloved drill that you don’t necessarily know.

Drill bit size can seem like a minor detail to most but it can actually be really important for deciding how your drill will perform. It can be a key factor of getting the best experience out of your drill. While it’s very important, it’s a detail that is often overlooked. Here will be showing you how to know what size drill to use.

Choosing Drill Bits By Type

Oftentimes, drill bits are classified by the materials they are made from. There are a wide range of drill bits made from a wide range of materials from high-speed steel which is used for things like wood and light metal to black oxide coated which is used for things like hardwoods and steel. ​

There’s also the matter of design of the drill bit. A twisted bit is the go-to for anyone looking for a bit capable of working on general home projects. Like the high-speed steel material, it is often used for wood and light metal. Another common design is the auger drill bit that is also used for boring into wood but is seen as an accessory that creates deeper boring. ​

How To Choose Drill Bits By Size

With most drill bits, there are charts that will allow you to more easily match the job with the drill bit size. It provides a guide for the consumer to follow that is meant to make the task easier.

Some general rules of thumb are to not use a bit exactly the size of the hole when working with wood, make it about 1/64” smaller. For other materials, use the correct size. If you’re not certain of which one applies to you then choose the 1/64” method which will let you play it safe. ​

If you need to know what size drill bit you need for a particular screw, use the following drill bit size chart:

Drilling Through Wo​​​​od

Drilling through wood is one of the most common uses of a drill. It is often the first thing people think of, and associate with the tool. 

Each material you plan to drill through requires its own considerations and specifications. Wood drill bits can be called the most common drill bits available.

These bits usually have a pointed tip and spurs on the sides for better capability to bore into the wood. Most materials will work for softwood but you will need more durable materials for hardwoods, an example being coated black oxide. ​

If you are a craftsman and your goal is drilling through wood accurately, then drill presses for working with wood are in general the best solution.

Q: What is Drill Bit Size

A: Drill bits themselves are the tools used to bore into the substance you plan to work with. It is the main part that comes into contact with your material and is in charge of executing the task.

Drill bit size determines how the hole you are trying to make will turn out. It takes into account things like drill diameter to come up with a fraction that will tell you the given size of the bit.

Q:  Can Masonry Drill Bit Be Used For Wood

A: The short answer: yes it can.

Masonry drills bits, while better for things like stone and brick, can, in fact, be used on wood. But when you use this kind of drill bit for something outside of what it is intended for, it can create rougher edges of the hole and progress the work at a slower pace.

Q:  How To Change a Drill Bit

A: Changing the drill bit is one of the most vital parts in being able to tailor them to the project you’re working on. You will need to know this through all types of bits and practices.

There are a few steps to this, and some vary among different drill designs, but here are a few basics to get you started.

1. First, you will need to loosen the chuck. The chuck is what holds the bit in place and is used as a connector. It is what is keeping your drill bit in place and is the key to extracting an already inserted bit.

2. After you’ve loosened the chuck, you will need to take out the drill bit from its place. It should be unsteady in its place. Once loosened you will just need to slide out the drill from its place. It should come out easy with little resistance.

3. Next put the desired drill bit in place of the old one. Make sure you choose the right one for your project depending on hole size and the material you are working with.

4. Then hold the new drill bit in place and press down on the trigger to tighten it. This is just a more efficient way to reinstate the drill bit and chuck back into place. If you want you can simply skip this step and go on to the next one.

5. Finally, double check that it is in place by twisting the chuck to ensure it’s in place. You can do this without having to do the previous step, the latter is just seen as more convenient for some.

And with that, you’ve successfully changed your drill bit. It’s as simple as one, two, three.

Q:  Can A Drill Bit Go Through Metal

A: Many drill bits are made to work with metal and other similar materials. The kind of drill bit you need depends a bit on the toughness of the metal. For light metals, you can use high-speed steel or for stronger metals, you can use a black oxide coated bit.

Q:  How To Determine Drill Bit Size

A: Anytime you buy a drill bit it should come with the correct sizes. But if you lose this information or your drill bit gets lost in clutter there are a couple of ways to determine this.

The drill bit size can be determined by using a drill bit size card. This card allows you to find the size by measuring it with the indents in the card.

If this is not something you think will work for you, another option is to look for the size etching at the base of the shank. These are on most if not all of the drill bits sold today.

Q:  Which Drill Bit Size Should I Use

A: There are many ways to determine what drill bit size you should use.

When working with wood make the bit about 1/64” smaller than the hole you plan to drill. With this in mind, when working with other materials use the correct size. You may still be unsure but, in this case, the most reliable option to do is to use a bit 1/64” smaller.

You may not have always put drill bit size as a priority when thinking about working on your projects, but hopefully, you might think differently now. Drill bit sizes really do make a difference and change how the job is approached. They can make or break your project and how you will work on them.

Drill bit size goes beyond simply choosing a bit that looks kind of similar to what you’re aiming for. It’s about finding a match that will make your work on the project easier and less complicated. It’s about making your job more effortless and providing you with the right tools you need.

Our goal is that with a quick read of this guide, you will be able to make more informed decisions about your drill bit and which one you will be using. We hope to provide you with the experience and information you need to work more efficiently on your project and understand how to know what size drill to use.

Resources and Further Reading

1. “How to Drill a Hole in Glass.” Family Handyman, Family Handyman, 7 Dec. 2017.
2. “Drilling Holes in Tile.” This Old House, 12 Apr. 2017.
3. “Drill Bit Sizes. Homerepairgeek
4. How To Choose The Right Drill Bit. Homeadvisor
5. Types of Drill Bits. Homedepot
6. Drill Bits Buying Guide. Lowe's